Furnace charger crane



Jan- 1967 R. B. MCCREADY ETAL 3,

FURNACE CHARGER CRANE Filed Feb. 23, 1965 3 Sheets-Sheet l w I O v u-KMT i u} z; a s

z A INVENTORS R055 8. MC CREADY BY KLAUS w. FORSTER ATTORNEYS Jan. 10,1967 R. B. M CREADY ETAL 3,297,170

FURNACE CHARGER CRANE Filed Feb. 23, 1965 3 Sheets-Sheet 5 wawigmmzmmgimiizinllk g s v-6l INVENTORS ROSS B. MC CREADY H64 BYKLAUS w. FORSTERATTORNEYS United States Patent 01 3,297,170 FURNACE CHARGER CRANE RossB. Vicilready, Alliance, and Klaus W. Forster,

Brecksvilie, Ohio, assignors to Karma Corporation, Alliance, Ohio, acorporation of Ohio Filed Feb. 23, 1965, Ser. No. 434,394 4 Claims. (Cl.212l4) The present invention relates to cranes and more particularly tooverhead traveling cranes especially designed for charging materialsinto basic oxygen furnaces and the like.

In charging basic oxygen furnaces in the manufacture of steel it is thepractice to periodically charge the furnace by dumping molten metal andscrap metal into the vessel of the furnace. Usually, the molten metal isdumped into the furnace by a conventional overhead bridge-type ladlecrane which handles the molten metal in ladles suspended from the cranetrolley by hoist cables. The scrap metal is usually dumped into thefurnace by ground supported equipment which transports the scrap metalto the furnace in rectangular boxes or like containers from which it isdumped into the furnace. To a limited extent scrap metal boxes have beentransported to and from the furnace and their contents dumped into thefurnace by overhead crane equipment similar to that used for handlingthe ladles of molten metal. This procedure, however, has not beensatisfactory because the movements of the crane incidental to moving thescrap box to the furnace causes the box to swing which prevents quickand ready alignment of the box with the furnace, and in dumping the box,the shift of the weight of the scrap further causes undesired swingingof the box. To charge the furnace with scrap metal using conventionaloverhead crane equipment is a relatively slow procedure and requiresconsiderable skill and care on the part of the crane operator. As aresult, it has been conventional to install relatively heavy groundsupported equipment for handling the scrap metal charging, whichequipment is expensive to install and maintain and occupies valuableworking space.

One of the principal objects of the present invention is the provisionof a new and improved overhead crane particularly designed for handlingscrap boxes and by use of which loaded scrap boxes can be quicklytransported to a furnace of the type referred to above, accuratelyaligned with the furnace vessel in dumping position and the scrapcontained therein dumped in the furnace.

Another of the objects of the present invention is to provide a new andimproved overhead crane comprising a movable trolley having cable typehoist means for sup porting and dumping a load, which trolley comprisesstructure depending therefrom arranged to receive the cable suspendedload when the load is hoisted to a given elevation and prevent orcontrol lateral movement of the load during maneuvering of the trolleyto bring the load to a predetermined position and/ or during the dumpingof the load.

Other objects and advantages of the invention will be ap parent from thefollowing description of preferred embodiments thereof, reference beingmade to the accompanying drawings in which:

FIG. 1 is a fragmentary side elevational view, with parts broken away,of a two crane installation embodying the present invention for dumpingmolten metal and scrap metal into a basic oxygen furnace, the vessel ofwhich is shown in phantom lines;

FIG. 2 is a fragmentary view, with parts broken away, of a portion ofthe crane, herein sometimes referred to as the scrap box crane, shown inFIG. 1 with the load in an elevated position;

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FIG. 3 is a sectional view of the crane shown in FIG. 2 with the load inthe elevated position approximately on the line 33, with parts brokenaway;

FIG. 4 is a sectional view approximately on the line 4-4 of FIG. 3;

FIG. 5 is a fragmentary side view similar to FIG. 2 showing anotherembodiment of the invention, and

FIG. 6 is a sectional view approximately on the line 6-6 of FIG. 5 withparts brokenaway.

Referring to the drawings, the installation illustrated comprises twooverhead traveling bridge type cranes A, B adapted for charging thevessel C shown in phantom lines, of a basic oxygen furnace with moltenmetal and scrap metal. The furnace and cranes are located in a building,not shown, and the bridges D, E of the crane A, B, respectively, aresupported on and travel from one location in the building to anotheralong the same runway comprising widely separated rails, only one ofwhich appears in the drawings. The crane runway rails are supported bysuitable elevated structures according to well-known practices. Thebridge D of the crane A comprises two beam members 14, 15 connected toend trucks supported by flanged wheels on the rails of the crane runway.The bridge is moved along the crane runway by driving mechanisms ofconventional construction controlled by an operator riding in a cab onthe crane, which cab, for the sake of simplicity, is not shown. Thecrane A thus far described including the drive mentioned may be of anysuitable conventional construction, such as the bridge typecranedescribed in United States Patent No. 3,095,829.

In addition to the bridge D, the crane A comprises a trolley F whichrides on rails supported on the top of the bridge beams 14 and 15,respectively, and driven by suitable power means, also under the controlof the crane operator, so that the trolley can be caused to move fromone end of the bridge to the other. The trolley F shown is identicalwith the trolley shown in United States Patent No. 3,111,228 andincludes a frame 20 which supports or carries two hoisting mechanisms,one designated generally as G constitutes the principal load liftingmechanism, which load in the embodiment shown is a ladle L and the otherdesignated generally as H constitutes the dumping mechanism for tiltingand dumping the load or ladle. The load lift hoist mechanism G shown hastwo sets of hoisting cables connected to a single cable drum mechanismextending transversely of the length of the crane bridge and driven byan electric motor, controlled by the crane operator, to raise or lower aload grab 26 comprising a cross beam or spreader structure 27 havingpulleys jou'rnaled in the ends thereof about which the hoist cables arereeved, and a pair of hooks 30 attached to opposite ends of the spreaderand depend therefrom for pivotally engaging trunnions on the load orladle L to be hoisted.

The load tilting hoist mechanism H comprises a hoisting cable 33 havingits opposite ends connected to a cable drum driven by an electric motorcontrolled by the crane operator. The cable 33 is reeved about a pair ofsheaves connected to a hook-like grab 38 and the center loop of thecable passes over a sheave connected to a frame supported in the cranetrolley for movement towards and from the main hoist cable drum so thatthe pull on the grab can be maintained substantially vertical during thedumping of the load, which in the present instance is the ladle L. Itbeing understood that the grab 38 is connected to the ladle tilt bracket39 connected to the ladle adjacent to its bottom at the side oppositeits pouring lip. As previously mentioned, the trolley F illustrated is,in construction and operation, like that shown and described in UnitedStates Patent No. 3,111,228. It is to be understood, however, that othertrolley arrangements may 3 be employed, for example, that shown inUnited States Patent No. 1,430,009.

The crane B illustrated including its trolley K, which travels on thebridge B comprising the beams or girders 40 and 41, is similar inconstruction and operation to the crane A except that the trolley islonger in the direction of its travel on the bridge so as to space theload lift hoist and the load tilting hoist mechanisms M and N fartherapart because the load to be handled, that is, the scrap box S is longerlengthwise of the bridge than the ladle L. It is to be understood,however, that the scrap box may be shorter or in fact longer than thebox S shown, as desired. The lengthening of the trolley K is preferablyaccomplished in such a manner that the movable member 42 which carriesthe sheave about which the center loop of the cable 43 is reeved canmove proportionately further than the corresponding member of thetrolley F. The only other difference between the trolleys F and K is theinclusion in the trolley K of means for receiving the load lift graband/ or the trunnions of the load and holding them against lateralmovement when the load has been raised to a predetermined position,which position in the present instance, is that required for dumping thescrap in the scrap box S into the furnace vessel C.

As previously mentioned in the operation of a furnace of the characterreferred to, molten metal and scrap metal are periodically dumped intothe top opening of the furnace vessel and in the arrangements disclosed,crane A is used to transport the molten metal in a conventional ladle Lfrom some point in the building to the furnace and dump the metal in thevessel of the furnace. For this purpose the trunnions of the ladle areengaged in the hooks 30 of the hoist mechanism G and the tilt bracket 39engaged by the grab 38. Both hoist mechanisms are operated to raise theladle to the desired elevation after which the ladle is tilted about theaxis of its trunnions by raising the brab 38 carried by the cable 33 todump the metal into the furnace opening.

The crane B which includes the trolley is employed to transfer the scrapboxes S to the furnace and dump the scrap metal therein into thefurnace. A number of boxes may be loaded with scrap metal in one or morelocations in the building and transported one at a time by crane B tothe furnace and the scrap therein dumped into the furnace. Box S is arectangular trough-like box having one end closed and the other endprovided with a discharge chute 50 for guiding or directing the scrapmetal out of the end of the box as the box is tilted in the manner shownin phantom lines in FIG. 2. The box S has a pair of axially alignedtrunnions 51 and 52 projecting from opposite sides and adjacent thechute end thereof to be engaged by the hooks 54 and 55 of the grab 56and a projecting assembly 57 on the opposite or closed end of the box tobe engaged by the grab 58. As previously stated the hook spacings ofgrabs 56 and 58 are duplicates of the hook spacings of grabs 27 and 38of the crane A.

When scrap boxes of the character referred to are handled by cranes,such as the crane A shown, as previously stated, the acceleration anddeceleration of the bridge and trolley in moving the boxes to thefurnace cause the suspended box to swing which prevents ready alignmentof the discharge chute of the boxes with the furnace opening, and aftera box has been aligned with the furnace, the tilting thereof and thefiow of the scrap therefrom shifts the weight suspended by the cableswhich tends to and usually does, swing the box out of alignment with thefurnace. To overcome these difiiculties, the trolley K has a guidestructure P attached thereto and projecting downwardly therebelow toreceive the ends of the spreader 56 and the hooks 54 and 55 when thegrab is raised a predetermined distance and which guide structurepositively prevents lateral movements of the hooks and consequently thesuspended scrap box carried thereby when the hooks are positionedtherein.

When the grab is in its elevated position in which the lower ends of thehooks are received in the guide structure, the scrap box moves exactlyin accordance with the movements of the bridge and/ or trolley and thecrane operator may quickly align the discharge chute of the box with thefurnace opening, and the alignment will be maintained throughout thescrap dumping operation.

Guide structure P shown comprises two members 60, 61 which may becastings or weldments welded or otherwise secured to and projectingdownwardly from the trolley frame adjacent to opposite sides thereof. Inthe embodiment shown both upper ends of the members 60 and 61 as viewedin FIG. 1 are connected by integral webs 62, 63 and 64 for stabilitypurposes. The guide members 60 and 61 comprise inwardly facing verticalgrooves or channels 65 and 66, respectively, extending to their lowerends adapted to receive the ends of the spreader structure 56 and thehooks 54 and 55. The guide members confine the ends of the grabincluding the hooks 54 and 55 when the grab is raised to engage withinthe channels 65, 66 and prevent movement thereof and the scrap box Srelative to the trolley in all directions except vertically. Preferably,the lower portions of the openings or channels 65 and 66 in the guidemembers are bevelled to facilitate entry of the grab thereinto.

The distance that the guide structure for the grab extends below thetrolley depends upon the distance from the trolley to the point aboutwhich the scrap box is pivoted in dumping its contents into the furnacevessel. While in the preferred embodiment of the invention shown theends of the spreader 56 and the hooks 54 and 55 are received in thechannels 65 and 66 of the guide structure K with very little clearance,preferably about one-half inch, on each of the three sides of thechannels, it will be apparent that it would be merely necessary toconfine the lower end of the hooks 54 and 55 or in fact merely thetrunnions of the scrap box because the scrap box pivots during dumpingabout the longitudinal axis of the trunnions. The crane B can also beused expeditiously to transport and dump the ladle L and when so usedthe ladle trunnions will be confined in the same manner as are thetrunnions of the scrap box S.

While in the preferred embodiment a spreader type grab is employed withthe principal hoist mechanisms it is to be understood that the spreadercould be eliminated and the hooks of the grab directly attached to thepulley blocks on the lower end of the cables and the cables rearrangedon the main hoist drum so that the hooks would enter the channels in theguide structure and be restrained thereby against lateral shifting.

FIGURES 5 and 6 show a modification of the trolley K shown in thepreferred embodiment wherein lower sheaves of the hoist cable means 70and 71, corresponding with the main hoist cable means of the preferredembodiment are directly connected to one-piece hooks 72 and 73,respectively, appreciable lengths of which are confined in the guidestructure R depending from the trolley. The guide structure R is in allessential respects similar to the guide structure P of the preferredembodiment, and comprises side members 75 and 76 having verticalchannels 77 and 78 therein within the lower ends of which the upper endsof the hooks 72 and 73 are received when the load is elevated to dumpingposition.

The scrap box T, shown in FIGURES 5 and 6, is similar to the scrap box Sexcept that the trunnions 80 and 81 are connected thereto by brackets 82and 83, respectively, instead of being directly connected to the boxproper. This construction is employed so that when the box T is dumpedit will not engage the downward projecting ends of the side members 75and 76 of the guide structure R. The trunnions could be connecteddirectly to the scrap box, if desired, and other parts of the apparatusmodified to permit dumping of the box. It will be noted that in theembodiment shown in FIGURES 5 and 6 the trunnions and the box, when thebox is elevated to dumping position, are below the lower ends of theside members 75 and 76 of the guide structure R. Alternatively, thehooks proper could be pivotally connected to pulley blocks having thelower sheaves of the cable means 70 and 71 connected thereto. In thisevent it would be necessary or desirable to have the dumping elevationof the load such that the lower ends of the hooks would be confinedwithin the guide channels of the guide structure R.

The tilting hoist mechanism employed in the embodiment shown in FIGURES5 and 6 is a duplicate of that forming a part of the trolley K of thepreferred embodiment and the duplicate parts are designated by the samereference characters.

It will be apparent from the foregoing that the present inventionprovides a traveling overhead crane that can be employed toexpeditiously charge scrap metal into a furnace thereby eliminating thenecessity of providing ground supported equipment for this purpose. Thecrane B shown can also be used for expeditiously transporting anddumping ladles. The crane A can be omitted from the installation ifdesired and the crane B employed for both charging operations.Alternatively, both trolleys may be made similar to trolley K in whichevent either crane would be available for either operation which wouldbe advantageous in the event of a breakdown of one of the cranes.

From the foregoing description of the preferred embodiments of theinvention it will be apparent that the objects, heretofore enumerated,and others have been accomplished and that there has been provided anovel and improved overhead apparatus for use in steel mills and thelike which not only does not occupy valuable floor space but which canbe used to quickly change molten and/ or scrap metal into a furnace thussaving valuable furnace operating time which would be othe lost.

Although the preferred embodiments of the invention have been shown anddescribed in considerable detail, it is to be understood that theinvention disclosed is not limited to the particular constructions shownand described, and it is the intention to hereby cover all adaptations,modifications and uses of the invention which come within the practiceof those skilled in the art to which the invention relates and the scopeof the appended claims.

Having described our invention, we claim:

1. In a crane having an overhead bridge, a crane trolley movable alongsaid bridge and including depending members forming guide means,auxiliary hoist mechanism on said trolley comprising auxiliary hoistflexible cable means, auxiliary load grab means adapted to be detachablyconnected to a load, said auxiliary load grab means being connected tosaid auxiliary hoist cable means, main hoist mechanism comprising mainhoist flexible cable means, and main load grab means adapted to bedetachably connected to a load, said main load grab means beingconnected to said main hoist cable means and movable vertically betweena position below and free of said guide means for connection to a loadand a position above the lower end of said guide means for moving anddischarging a load while suspended from said trolley by said main andauxiliary cable means, said guide means being operative to restrainlateral movement of a load carried by said main and auxiliaty load grabmeans when said main grab means is elevated to a position above thelower end of said guide means, said auxiliary load grab means beingvertically movable relative to said trolley independently of said mainload grab means.

2. In a crane, a trolley movable along an overhead trackway andcomprising a frame including depending guide means providing generallyvertical guideways, auxiliary hoist mechanism on said trolley comprisingauxiliary hoist flexible cable means, auxiliary load grab means adaptedto be detachably connected to a load, said auxiliary load grab meansbeing connected to said auxiliary hoist cable means, main hoistmechanism on said trolley comprising main hoist flexible cable means,and main grab means adapted to be detachably connected to a loadoperatively connected to said main hoist cable means and movablevertically between a position without and clear of said guide-ways forconnection to a load, and to a position within said guide-ways formoving and discharging a load while suspended from said trolley by saidmain and auxiliary cable means, said guide means being operative toprevent lateral movement of a load relative to said trolley suspendedtherefrom by said main and auxiliary cable means when said main grabmeans is within said guide-ways, said auxiliary load grab means beingvertically movable relative to said trolley independently of said mainload grab means.

3. In a material handling apparatus as defined in claim 1 wherein saidguide means comprise generally vertically extending, spaced channel-likeguide-ways facing one another formed in said guide means depending fromsaid trolley.

d. In a material handling apparatus as defined in claim 2 in which saidgrab means are hook-type grabs detachably engageable with projections onsaid load, said projections engageable with said main grab means havingportions movable into said guide means.

References Cited by the Examiner UNITED STATES PATENTS 1,362,560 12/1920Coe 212 1,558,746 10/1925 Moore 212-430 3,034,659 5/1962 Willison et al.2l2--14 3,111,228 11/1963 Anderson 212l30 ANDRES H. NIELSEN, PrimaryExaminer.

EVON C. BLUNK, Examiner.

A. L. LEVINE, Assistant Examiner.

1. IN A CRANE HAVING AN OVERHEAD BRIDGE, A CRANE TROLLEY MOVABLE ALONGSAID BRIDGE AND INCLUDING DEPENDING MEMBERS FORMING GUIDE MEANS,AUXILIARY HOIST MECHANISM ON SAID TROLLEY COMPRISING AUXILIARY HOISTFLEXIBLE CABLE MEANS, AUXILIARY LOAD GRAB MEANS ADAPTED TO BE DETACHABLYCONNECTED TO A LOAD, SAID AUXILIARY LOAD GRAB MEANS BEING CONNECTED TOSAID AUXILIARY HOIST CABLE MEANS, MAIN HOIST MECHANISM COMPRISING MAINHOIST FLEXIBLE CABLE MEANS, AND MAIN LOAD GRAB MEANS ADAPTED TO BEDETACHABLY CONNECTED TO A LOAD, SAID MAIN LOAD GRAB MEANS BEINGCONNECTED TO SAID MAIN HOIST CABLE MEANS AND MOVABLE VERTICALLY BETWEENA POSITION BELOW AND FREE OF SAID GUIDE MEANS FOR CONNECTION TO A LOADAND A POSITION ABOVE THE LOWER END OF SAID GUIDE MEANS FOR MOVING ANDDISCHARGING A LOAD WHILE SUSPENDED FROM SAID TROLLEY BY SAID MAIN ANDAUXILIARY CABLE MEANS, SAID GUIDE MEANS BEING OPERATIVE TO RESTRAINLATERAL MOVEMENT OF A LOAD CARRIED BY SAID MAIN AND AUXILIARY LOAD GRABMEANS WHEN SAID MAIN GRAB MEANS IS ELEVATED TO A POSITION ABOVE THELOWER END OF SAID GUIDE MEANS, SAID AUXILIARY LOAD GRAB MEANS BEINGVERTICALLY MOVABLE RELATIVE TO SAID TROLLEY INDEPENDENTLY OF SAID MAINLOAD GRAB MEANS.